Why does water disappear from an open container?
You have examined the physical process of evaporation.....i.e.
Now you had an open system, and the water vapour (or ethanol vapur, or whatever the solvent was) could expand to fill the room, and over 24-48 hours it entirely evaporated. Now you started with a solution, in which there was some involatile solute (what does
The solute came out of solution as the water (?) slowly evaporated, to give a solid residue.....
I bet the stuff was copper sulfate, which forms lovely blue crystals of